On food and cooking_ the science and lore of the kitchen.

by Harold McGee.

Acknowledgments.

Along with many food writers today, I feel a great debt of grat.i.tude to Alan Davidson for the way he brought new substance, scope, and playfulness to our subject. On top of that, it was Alan who informed me that I would have to revise On Food and Cooking On Food and Cooking - before I'd even held the first copy in my hands! At our first meeting in 1984, over lunch, he asked me what the book had to say about fish. I told him that I mentioned fish in pa.s.sing as one form of animal muscle and thus of meat. And so this great fish enthusiast and renowned authority on the creatures of several seas gently suggested that, in view of the fact that fish are diverse creatures and their flesh very unlike meat, they really deserve special and extended attention. Well, yes, they really do. There are many reasons for wishing that this revision hadn't taken as long as it did, and one of the biggest is the fact that I can't show Alan the new chapter on fish. I'll always be grateful to Alan and to Jane for their encouragement and advice, and for the years of friendship which began with that lunch. This book and my life would have been much poorer without them. - before I'd even held the first copy in my hands! At our first meeting in 1984, over lunch, he asked me what the book had to say about fish. I told him that I mentioned fish in pa.s.sing as one form of animal muscle and thus of meat. And so this great fish enthusiast and renowned authority on the creatures of several seas gently suggested that, in view of the fact that fish are diverse creatures and their flesh very unlike meat, they really deserve special and extended attention. Well, yes, they really do. There are many reasons for wishing that this revision hadn't taken as long as it did, and one of the biggest is the fact that I can't show Alan the new chapter on fish. I'll always be grateful to Alan and to Jane for their encouragement and advice, and for the years of friendship which began with that lunch. This book and my life would have been much poorer without them.

I would also have liked to give this book to Nicholas Kurti - bracing myself for the discussion to come! Nicholas wrote a heartwarmingly positive review of the first edition in Nature, Nature, then followed it up with a Sunday-afternoon visit and an extended interrogation based on the pages of questions that he had acc.u.mulated as he wrote the review. Nicholas's energy, curiosity, and enthusiasm for good food and the telling "little experiment" were infectious, and animated the early Erice workshops. They and he are much missed. then followed it up with a Sunday-afternoon visit and an extended interrogation based on the pages of questions that he had acc.u.mulated as he wrote the review. Nicholas's energy, curiosity, and enthusiasm for good food and the telling "little experiment" were infectious, and animated the early Erice workshops. They and he are much missed.

Coming closer to home and the present, I thank my family for the affection and patient optimism that have kept me going day after day: son John and daughter Florence, who have lived with this book and experimental dinners for more than half their years, and enlivened both with their gusto and strong opinions; my father, Chuck McGee, and mother, Louise Hammersmith; brother Michael and sisters Ann and Joan; and Chuck Hammersmith, Werner Kurz, Richard Thomas, and Florence Jean and Harold Long. Throughout these last few trying years, my wife Sharon Long has been constantly caring and supportive. I'm deeply grateful to her for that gift.

Milly Marmur, my onetime publisher, longtime agent, and now great friend, has been a source of propulsive energy over the course of a marathon whose length neither of us foresaw. I've been lucky to enjoy her warmth, patience, good sense, and her skill at nudging without noodging.

I owe thanks to many people at Scribner and Simon & Schuster. Maria Guarnasch.e.l.li commissioned this revision with inspiring enthusiasm, and Scribner publisher Susan Moldow and S&S president Carolyn Reidy have been its committed advocates ever since. Beth Wareham tirelessly supervised all aspects of editing, production, and publication. Rica Buxbaum Allannic made many improvements in the ma.n.u.script with her careful editing; Mia Crowley-Hald and her team produced the book under tough time constraints with meticulous care; and Erich Hobbing welcomed my ideas about layout and designed pages that flow well and read clearly. Jeffrey Wilson kept contractual and other legal matters smooth and peaceful, and Lucy Kenyon organized some wonderful early publicity. I appreciate the marvelous team effort that has launched this book into the world.

I thank Patricia Dorfman and Justin Greene for preparing the ill.u.s.trations with patience, skill, and speed, and Ann Hirsch, who produced the micrograph of a wheat kernel for this book. I'm happy to be able to include a few line drawings from the first edition by my sister Ann, who has been prevented by illness from contributing to this revision. She was a wonderful collaborator, and I've missed her sharp eye and good humor very much. I'm grateful to several food scientists for permission to share their photographs of food structure and microstructure: they are H. Douglas Goff, R. Carl Hoseney, Donald D. Kasarda, William D. Powrie, and Alastair T. Pringle. Alexandra Nickerson expertly compiled some of the most important pages in this book, the index.

Several chefs have been kind enough to invite me into their kitchens - or laboratories - to experience and talk about cooking at its most ambitious. My thanks to Fritz Blank, to Heston Blumenthal, and especially to Thomas Keller and his colleagues at The French Laundry, including Eric Ziebold, Devin Knell, Ryan Fancher, and Donald Gonzalez. I've learned a lot from them, and look forward to learning much more.

Particular sections of this book have benefited from the careful reading and comments of Anju and Hiten Bhaya, Devaki Bhaya and Arthur Grossman, Poornima and Arun k.u.mar, Sharon Long, Mark Pastore, Robert Steinberg, and Kathleen, Ed, and Aaron Weber. I'm very grateful for their help, and absolve them of any responsibility for what I've done with it.

I'm glad for the chance to thank my friends and my colleagues in the worlds of writing and food, all sources of stimulating questions, answers, ideas, and encouragement over the years: Shirley and Arch Corriher, the best of company on the road, at the podium, and on the phone; Lubert Stryer, who gave me the chance to see the science of pleasure advanced and immediately applied; and Kurt and Adrienne Alder, Peter Barham, Gary Beauchamp, Ed Behr, Paul Bertolli, Tony Blake, Glynn Christian, Jon Eldan, Anya Fernald, Len Fisher, Alain Harrus, Randolph Hodgson, Philip and Mary Hyman, John Paul Khoury, Kurt Koessel, Aglaia Kremezi, Anna Tasca Lanza, David Lockwood, Jean Matricon, Fritz Maytag, Jack McInerney, Alice Medrich, Marion Nestle, Ugo and Beatrice Palma, Alan Parker, Daniel Patterson, Thorvald Pedersen, Charles Perry, Maricel Presilla, P.N. Ravindran, Judy Rodgers, Nick Ruello, Helen Saberi, Mary Taylor Simeti, Melpo Skoula, Anna and Jim Spudich, Jeffrey Steingarten, Jim Tavares, Herve This, Bob Togasaki, Rick Vargas, Despina Vokou, Ari Weinzweig, Jonathan White, Paula Wolfert, and Richard Zare.

Finally, I thank Soyoung Scanlan for sharing her understanding of cheese and of traditional forms of food production, for reading many parts of the ma.n.u.script and helping me clarify both thought and expression, and above all for reminding me, when I had forgotten, what writing and life are all about.

The everyday alchemy of creating food for the body and the mind. This 17th century woodcut compares the alchemical ("chymick") work of the bee and the scholar, who transform nature's raw materials into honey and knowledge. Whenever we cook we become practical chemists, drawing on the acc.u.mulated knowledge of generations, and transforming what the Earth offers us into more concentrated forms of pleasure and nourishment. (The first Latin caption reads "Thus we bees make honey, not for ourselves"; the second, "All things in books," the library being the scholar's hive. Woodcut from the collection of the International Bee Research a.s.sociation.)

Introduction.

Cooking and Science, 1984 and 2004.

This is the revised and expanded second edition of a book that I first published in 1984, twenty long years ago. In 1984, canola oil and the computer mouse and compact discs were all novelties. So was the idea of inviting cooks to explore the biological and chemical insides of foods. It was a time when a book like this really needed an introduction!

Twenty years ago the worlds of science and cooking were neatly compartmentalized. There were the basic sciences, physics and chemistry and biology, delving deep into the nature of matter and life. There was food science, an applied science mainly concerned with understanding the materials and processes of industrial manufacturing. And there was the world of small-scale home and restaurant cooking, traditional crafts that had never attracted much scientific attention. Nor did they really need any. Cooks had been developing their own body of practical knowledge for thousands of years, and had plenty of reliable recipes to work with.

I had been fascinated by chemistry and physics when I was growing up, experimented with electroplating and Tesla coils and telescopes, and went to Caltech planning to study astronomy. It wasn't until after I'd changed directions and moved on to English literature - and had begun to cook - that I first heard of food science. At dinner one evening in 1976 or 1977, a friend from New Orleans wondered aloud why dried beans were such a problematic food, why indulging in red beans and rice had to cost a few hours of sometimes embarra.s.sing discomfort. Interesting question! A few days later, working in the library and needing a break from 19th century poetry, I remembered it and the answer a biologist friend had dug up (indigestible sugars), thought I would browse in some food books, wandered over to that section, and found shelf after shelf of strange t.i.tles. Journal of Food Science. Poultry Science. Cereal Chemistry. Journal of Food Science. Poultry Science. Cereal Chemistry. I flipped through a few volumes, and among the mostly bewildering pages found hints of answers to other questions that had never occurred to me. Why do eggs solidify when we cook them? Why do fruits turn brown when we cut them? Why is bread dough bouncily alive, and why does bounciness make good bread? Which kinds of dried beans are the worst offenders, and how can a cook tame them? It was great fun to make and share these little discoveries, and I began to think that many people interested in food might enjoy them. Eventually I found time to immerse myself in food science and history and write I flipped through a few volumes, and among the mostly bewildering pages found hints of answers to other questions that had never occurred to me. Why do eggs solidify when we cook them? Why do fruits turn brown when we cut them? Why is bread dough bouncily alive, and why does bounciness make good bread? Which kinds of dried beans are the worst offenders, and how can a cook tame them? It was great fun to make and share these little discoveries, and I began to think that many people interested in food might enjoy them. Eventually I found time to immerse myself in food science and history and write On Food and Cooking: The Science and Lore of the Kitchen. On Food and Cooking: The Science and Lore of the Kitchen.

As I finished, I realized that cooks more serious than my friends and I might be skeptical about the relevance of cells and molecules to their craft. So I spent much of the introduction trying to bolster my case. I began by quoting an unlikely trio of authorities, Plato, Samuel Johnson, and Jean Anthelme Brillat-Savarin, all of whom suggested that cooking deserves detailed and serious study. I pointed out that a 19th century German chemist still influences how many people think about cooking meat, and that around the turn of the 20th century, Fannie Farmer began her cookbook with what she called "condensed scientific knowledge" about ingredients. I noted a couple of errors in modern cookbooks by Madeleine Kamman and Julia Child, who were ahead of their time in taking chemistry seriously. And I proposed that science can make cooking more interesting by connecting it with the basic workings of the natural world.

A lot has changed in twenty years! It turned out that On Food and Cooking On Food and Cooking was riding a rising wave of general interest in food, a wave that grew and grew, and knocked down the barriers between science and cooking, especially in the last decade. Science has found its way into the kitchen, and cooking into laboratories and factories. was riding a rising wave of general interest in food, a wave that grew and grew, and knocked down the barriers between science and cooking, especially in the last decade. Science has found its way into the kitchen, and cooking into laboratories and factories.

In 2004 food lovers can find the science of cooking just about everywhere. Magazines and newspaper food sections devote regular columns to it, and there are now a number of books that explore it, with Shirley Corriher's 1997 CookWise CookWise remaining unmatched in the way it integrates explanation and recipes. Today many writers go into the technical details of their subjects, especially such intricate things as pastry, chocolate, coffee, beer, and wine. Kitchen science has been the subject of television series aired in the United States, Canada, the United Kingdom, and France. And a number of food molecules and microbes have become familiar figures in the news, both good and bad. Anyone who follows the latest in health and nutrition knows about the benefits of antioxidants and phytoestrogens, the hazards of trans fatty acids, acrylamide, remaining unmatched in the way it integrates explanation and recipes. Today many writers go into the technical details of their subjects, especially such intricate things as pastry, chocolate, coffee, beer, and wine. Kitchen science has been the subject of television series aired in the United States, Canada, the United Kingdom, and France. And a number of food molecules and microbes have become familiar figures in the news, both good and bad. Anyone who follows the latest in health and nutrition knows about the benefits of antioxidants and phytoestrogens, the hazards of trans fatty acids, acrylamide, E. coli E. coli bacteria, and mad cow disease. bacteria, and mad cow disease.

Professional cooks have also come to appreciate the value of the scientific approach to their craft. In the first few years after On Food and Cooking On Food and Cooking appeared, many young cooks told me of their frustration in trying to find out appeared, many young cooks told me of their frustration in trying to find out why why dishes were prepared a certain way, or why ingredients behave as they do. To their traditionally trained chefs and teachers, understanding food was less important than mastering the tried and true techniques for preparing it. Today it's clearer that curiosity and understanding make their own contribution to mastery. A number of culinary schools now offer "experimental" courses that investigate the whys of cooking and encourage critical thinking. And several highly regarded chefs, most famously Ferran Adria in Spain and Heston Blumenthal in England, experiment with industrial and laboratory tools - gelling agents from seaweeds and bacteria, non-sweet sugars, aroma extracts, pressurized gases, liquid nitrogen - to bring new forms of pleasure to the table. dishes were prepared a certain way, or why ingredients behave as they do. To their traditionally trained chefs and teachers, understanding food was less important than mastering the tried and true techniques for preparing it. Today it's clearer that curiosity and understanding make their own contribution to mastery. A number of culinary schools now offer "experimental" courses that investigate the whys of cooking and encourage critical thinking. And several highly regarded chefs, most famously Ferran Adria in Spain and Heston Blumenthal in England, experiment with industrial and laboratory tools - gelling agents from seaweeds and bacteria, non-sweet sugars, aroma extracts, pressurized gases, liquid nitrogen - to bring new forms of pleasure to the table.

As science has gradually percolated into the world of cooking, cooking has been drawn into academic and industrial science. One effective and charming force behind this movement was Nicholas Kurti, a physicist and food lover at the University of Oxford, who lamented in 1969: "I think it is a sad reflection on our civilization that while we can and do measure the temperature in the atmosphere of Venus, we do not know what goes on inside our souffles." In 1992, at the age of 84, Nicholas nudged civilization along by organizing an International Workshop on Molecular and Physical Gastronomy at Erice, Sicily, where for the first time professional cooks, basic scientists from universities, and food scientists from industry worked together to advance gastronomy, the making and appreciation of foods of the highest quality.

The Erice meeting continues, renamed the "International Workshop on Molecular Gastronomy 'N. Kurti' " in memory of its founder. And over the last decade its focus, the understanding of culinary excellence, has taken on new economic significance. The modern industrial drive to maximize efficiency and minimize costs generally lowered the quality and distinctiveness of food products: they taste much the same, and not very good. Improvements in quality can now mean a compet.i.tive advantage; and cooks have always been the world's experts in the applied science of deliciousness. Today, the French National Inst.i.tute of Agricultural Research sponsors a group in Molecular Gastronomy at the College de France (its leader, Herve This, directs the Erice workshop); chemist Thorvald Pedersen is the inaugural Professor of Molecular Gastronomy at Denmark's Royal Veterinary and Agricultural University; and in the United States, the rapidly growing membership of the Research Chefs a.s.sociation specializes in bringing the chef's skills and standards to the food industry.

So in 2004 there's no longer any need to explain the premise of this book. Instead, there's more for the book itself to explain! Twenty years ago, there wasn't much demand for information about extra-virgin olive oil or balsamic vinegar, farmed salmon or gra.s.s-fed beef, cappuccino or white tea, Sichuan pepper or Mexican mole, sake or well-tempered chocolate. Today there's interest in all these and much more. And so this second edition of On Food and Cooking On Food and Cooking is substantially longer than the first. I've expanded the text by two thirds in order to cover a broader range of ingredients and preparations, and to explore them in greater depth. To make room for new information about foods, I've dropped the separate chapters on human physiology, nutrition, and additives. Of the few sections that survive in similar form from the first edition, practically all have been rewritten to reflect fresh information, or my own fresh understanding. is substantially longer than the first. I've expanded the text by two thirds in order to cover a broader range of ingredients and preparations, and to explore them in greater depth. To make room for new information about foods, I've dropped the separate chapters on human physiology, nutrition, and additives. Of the few sections that survive in similar form from the first edition, practically all have been rewritten to reflect fresh information, or my own fresh understanding.

This edition gives new emphasis to two particular aspects of food. The first is the diversity of ingredients and the ways in which they're prepared. These days the easy movement of products and people makes it possible for us to taste foods from all over the world. And traveling back in time through old cookbooks can turn up forgotten but intriguing ideas. I've tried throughout to give at least a brief indication of the range of possibilities offered by foods themselves and by different national traditions.

The other new emphasis is on the flavors of foods, and sometimes on the particular molecules that create flavor. Flavors are something like chemical chords, composite sensations built up from notes provided by different molecules, some of which are found in many foods. I give the chemical names of flavor molecules when I think that being specific can help us notice flavor relationships and echoes. The names may seem strange and intimidating at first, but they're just names and they'll become more familiar. Of course people have made and enjoyed well seasoned dishes for thousands of years with no knowledge of molecules. But a dash of flavor chemistry can help us make fuller use of our senses of taste and smell, and experience more - and find more pleasure - in what we cook and eat.

Now a few words about the scientific approach to food and cooking and the organization of this book. Like everything on earth, foods are mixtures of different chemicals, and the qualities that we aim to influence in the kitchen - taste, aroma, texture, color, nutritiousness - are all manifestations of chemical properties. Nearly two hundred years ago, the eminent gastronome Jean Anthelme Brillat-Savarin lectured his cook on this point, tongue partly in cheek, in The Physiology of Taste The Physiology of Taste: You are a little opinionated, and I have had some trouble in making you understand that the phenomena which take place in your laboratory are nothing other than the execution of the eternal laws of nature, and that certain things which you do without thinking, and only because you have seen others do them, derive nonetheless from the highest scientific principles.

The great virtue of the cook's time-tested, thought-less recipes is that they free us from the distraction of having to guess or experiment or a.n.a.lyze as we prepare a meal. On the other hand, the great virtue of thought and a.n.a.lysis is that they free us from the necessity of following recipes, and help us deal with the unexpected, including the inspiration to try something new. Thoughtful cooking means paying attention to what our senses tell us as we prepare it, connecting that information with past experience and with an understanding of what's happening to the food's inner substance, and adjusting the preparation accordingly.

To understand what's happening within a food as we cook it, we need to be familiar with the world of invisibly small molecules and their reactions with each other. That idea may seem daunting. There are a hundred-plus chemical elements, many more combinations of those elements into molecules, and several different forces that rule their behavior. But scientists always simplify reality in order to understand it, and we can do the same. Foods are mostly built out of just four kinds of molecules - water, proteins, carbohydrates, and fats. And their behavior can be pretty well described with a few simple principles. If you know that heat is a manifestation of the movements of molecules, and that sufficiently energetic collisions disrupt the structures of molecules and eventually break them apart, then you're very close to understanding why heat solidifies eggs and makes foods tastier.

Most readers today have at least a vague idea of proteins and fats, molecules and energy, and a vague idea is enough to follow most of the explanations in the first 13 chapters, which cover common foods and ways of preparing them. Chapters 14 and 15 then describe in some detail the molecules and basic chemical processes involved in all cooking; and the Appendix gives a brief refresher course in the basic vocabulary of science. You can refer to these final sections occasionally, to clarify the meaning of pH or protein coagulation as you're reading about cheese or meat or bread, or else read through them on their own to get a general introduction to the science of cooking.

Finally, a request. In this book I've sifted through and synthesized a great deal of information, and have tried hard to double-check both facts and my interpretations of them. I'm greatly indebted to the many scientists, historians, linguists, culinary professionals, and food lovers on whose learning I've been able to draw. I will also appreciate the help of readers who notice errors that I've made and missed, and who let me know so that I can correct them. My thanks in advance.

As I finish this revision and think about the endless work of correcting and perfecting, my mind returns to the first Erice workshop and a saying shared by Jean-Pierre Philippe, a chef from Les Mesnuls, near Versailles. The subject of the moment was egg foams. Chef Philippe told us that he had thought he knew everything there was to know about meringues, until one day a phone call distracted him and he left his mixer running for half an hour. Thanks to the excellent result and to other surprises throughout his career, he said, Je sais, je sais que je sais jamais: Je sais, je sais que je sais jamais: "I know, I know that I never know." Food is an infinitely rich subject, and there's always something about it to understand better, something new to discover, a fresh source of interest, ideas, and delight. "I know, I know that I never know." Food is an infinitely rich subject, and there's always something about it to understand better, something new to discover, a fresh source of interest, ideas, and delight.

A Note About Units of Measurement, and About the Drawings of MoleculesThroughout this book, temperatures are given in both degrees Fahrenheit (F), the standard units in the United States, and degrees Celsius or Centigrade (C), the units used by most other countries. The Fahrenheit temperatures shown in several charts can be converted to Celsius by using the formula C = (F-32) x 0.56. Volumes and weights are given in both U.S. kitchen units - teaspoons, quarts, pounds - and metric units - milliliters, liters, grams, and kilograms. Lengths are generally given in millimeters (mm); 1 mm is about the diameter of the degree symbol . Very small lengths are given in microns (). One micron is 1 micrometer, or 1 thousandth of a millimeter.Single molecules are so small, a tiny fraction of a micron, that they can seem abstract, hard to imagine. But they are real and concrete, and have particular structures that determine how they - and the foods made out of them - behave in the kitchen. The better we can visualize what they're like and what happens to them, the easier it is to understand what happens in cooking. And in cooking it's generally a molecule's overall shape that matters, not the precise placement of each atom. In most of the drawings of molecules in this book, only the overall shapes are shown, and they're represented in different ways - as long thin lines, long thick lines, honeycomb-like rings with some atoms indicated by letters - depending on what behavior needs to be explained. Many food molecules are built from a backbone of interconnected carbon atoms, with a few other kinds of atoms (mainly hydrogen and oxygen) projecting from the backbone. The carbon backbone is what creates the overall structure, so often it is drawn with no indications of the atoms themselves, just lines that show the bonds between atoms.

Chapter 1.

Milk and Dairy Products

Mammals and Milk.

The Evolution of MilkThe Rise of the RuminantsDairy Animals of the WorldThe Origins of DairyingDiverse Traditions Milk and Health Milk NutrientsMilk in Infancy and Childhood: Nutrition and AllergiesMilk after Infancy: Dealing with LactoseNew Questions about Milk Milk Biology and Chemistry How the Cow Makes MilkMilk Sugar: LactoseMilk FatMilk Proteins: Coagulation by Acid and EnzymesMilk Flavor Unfermented Dairy Products MilksCreamb.u.t.ter and MargarineIce Cream Fresh Fermented Milks and Creams Lactic Acid BacteriaFamilies of Fresh Fermented MilksYogurtSoured Creams and b.u.t.termilk, Including Creme FraicheCooking with Fermented Milks Cheese The Evolution of CheeseThe Ingredients of CheeseMaking CheeseThe Sources of Cheese DiversityChoosing, Storing, and Serving CheeseCooking with CheeseProcess and Low-fat CheesesCheese and Health What better subject for the first chapter than the food with which we all begin our lives? Humans are mammals, a word that means "creatures of the breast," and the first food that any mammal tastes is milk. Milk is food for the beginning eater, a gulpable essence distilled by the mother from her own more variable and challenging diet. When our ancestors took up dairying, they adopted the cow, the ewe, and the goat as surrogate mothers. These creatures accomplish the miracle of turning meadow and straw into buckets of human nourishment. And their milk turned out to be an elemental fluid rich in possibility, just a step or two away from luxurious cream, fragrant golden b.u.t.ter, and a mult.i.tude of flavorful foods concocted by friendly microbes.

No wonder that milk captured the imaginations of many cultures. The ancient Indo-Europeans were cattle herders who moved out from the Caucasian steppes to settle vast areas of Eurasia around 3000 BCE BCE; and milk and b.u.t.ter are prominent in the creation myths of their descendents, from India to Scandinavia. Peoples of the Mediterranean and Middle East relied on the oil of their olive tree rather than b.u.t.ter, but milk and cheese still figure in the Old Testament as symbols of abundance and creation.

The modern imagination holds a very different view of milk! Ma.s.s production turned it and its products from precious, marvelous resources into ordinary commodities, and medical science stigmatized them for their fat content. Fortunately a more balanced view of dietary fat is developing; and traditional versions of dairy foods survive. It's still possible to savor the remarkable foods that millennia of human ingenuity have teased from milk. A sip of milk itself or a scoop of ice cream can be a Proustian draft of youth's innocence and energy and possibility, while a morsel of fine cheese is a rich meditation on maturity, the fulfillment of possibility, the way of all flesh.

Mammals and Milk The Evolution of Milk How and why did such a thing as milk ever come to be? It came along with warm-bloodedness, hair, and skin glands, all of which distinguish mammals from reptiles. Milk may have begun around 300 million years ago as a protective and nourishing skin secretion for hatchlings being incubated on their mother's skin, as is true for the platypus today. Once it evolved, milk contributed to the success of the mammalian family. It gives newborn animals the advantage of ideally formulated food from the mother even after birth, and therefore the opportunity to continue their physical development outside the womb. The human species has taken full advantage of this opportunity: we are completely helpless for months after birth, while our brains finish growing to a size that would be difficult to accommodate in the womb and birth ca.n.a.l. In this sense, milk helped make possible the evolution of our large brain, and so helped make us the unusual animals we are.

Milk and b.u.t.ter: Primal FluidsWhen the G.o.ds performed the sacrifice, with the first Man as the offering, spring was the melted b.u.t.ter, summer the fuel, autumn the offering. They anointed that Man, born at the beginning, as a sacrifice on the straw.... From that full sacrifice they gathered the grains of b.u.t.ter, and made it into the creatures of the air, the forest, and the village...cattle were born from it, and sheep and goats were born from it.- The Rg Veda, Rg Veda, Book 10, ca. 1200 Book 10, ca. 1200 BCE BCE...I am come down to deliver [my people] out of the hands of the Egyptians, and to bring them up out of that land unto a good land and a large, unto a land flowing with milk and honey....- G.o.d to Moses on Mount h.o.r.eb (Exodus 3:8)Hast thou not poured me out as milk, and curdled me like cheese?- Job to G.o.d (Job 10:10) The Rise of the Ruminants All mammals produce milk for their young, but only a closely related handful have been exploited by humans. Cattle, water buffalo, sheep, goats, camels, yaks: these suppliers of plenty were created by a scarcity of food. Around 30 million years ago, the earth's warm, moist climate became seasonally arid. This shift favored plants that could grow quickly and produce seeds to survive the dry period, and caused a great expansion of gra.s.slands, which in the dry seasons became a sea of desiccated, fibrous stalks and leaves. So began the gradual decline of the horses and the expansion of the deer family, the ruminants, ruminants, which evolved the ability to survive on dry gra.s.s. Cattle, sheep, goats, and their relatives are all ruminants. which evolved the ability to survive on dry gra.s.s. Cattle, sheep, goats, and their relatives are all ruminants.

The key to the rise of the ruminants is their highly specialized, multichamber stomach, which accounts for a fifth of their body weight and houses trillions of fiber-digesting microbes, most of them in the first chamber, or rumen. rumen. Their unique plumbing, together with the habit of regurgitating and rechewing partly digested food, allows ruminants to extract nourishment from high-fiber, poor-quality plant material. Ruminants produce milk copiously on feed that is otherwise useless to humans and that can be stockpiled as straw or silage. Without them there would be no dairying. Their unique plumbing, together with the habit of regurgitating and rechewing partly digested food, allows ruminants to extract nourishment from high-fiber, poor-quality plant material. Ruminants produce milk copiously on feed that is otherwise useless to humans and that can be stockpiled as straw or silage. Without them there would be no dairying.

Dairy Animals of the World Only a small handful of animal species contributes significantly to the world's milk supply.

The Cow, European and Indian The immediate ancestor of The immediate ancestor of Bos taurus, Bos taurus, the common dairy cow, was the common dairy cow, was Bos primigenius, Bos primigenius, the long-horned wild aurochs. This ma.s.sive animal, standing 6 ft/180 cm at the shoulder and with horns 6.5 in/17 cm in diameter, roamed Asia, Europe, and North Africa in the form of two overlapping races: a humpless European-African form, and a humped central Asian form, the zebu. The European race was domesticated in the Middle East around 8000 the long-horned wild aurochs. This ma.s.sive animal, standing 6 ft/180 cm at the shoulder and with horns 6.5 in/17 cm in diameter, roamed Asia, Europe, and North Africa in the form of two overlapping races: a humpless European-African form, and a humped central Asian form, the zebu. The European race was domesticated in the Middle East around 8000 BCE BCE, the heat- and parasite-tolerant zebu in south-central Asia around the same time, and an African variant of the European race in the Sahara, probably somewhat later.

In its princ.i.p.al homeland, central and south India, the zebu has been valued as much for its muscle power as its milk, and remains rangy and long-horned. The European dairy cow has been highly selected for milk production at least since 3000 BCE BCE, when confinement to stalls in urban Mesopotamia and poor winter feed led to a reduction in body and horn size. To this day, the prized dairy breeds - Jerseys, Guernseys, Brown Swiss, Holsteins - are short-horned cattle that put their energy into making milk rather than muscle and bone. The modern zebu is not as copious a producer as the European breeds, but its milk is 25% richer in b.u.t.terfat.

The Buffalo The water buffalo is relatively unfamiliar in the West but the most important bovine in tropical Asia. The water buffalo is relatively unfamiliar in the West but the most important bovine in tropical Asia. Bubalus bubalis Bubalus bubalis was domesticated as a draft animal in Mesopotamia around 3000 was domesticated as a draft animal in Mesopotamia around 3000 BCE BCE, then taken to the Indus civilizations of present-day Pakistan, and eventually through India and China. This tropical animal is sensitive to heat (it wallows in water to cool down), so it proved adaptable to milder climates. The Arabs brought buffalo to the Middle East around 700 CE CE, and in the Middle Ages they were introduced throughout Europe. The most notable vestige of that introduction is a population approaching 100,000 in the Campagna region south of Rome, which supplies the milk for true mozzarella cheese, mozzarella di bufala. mozzarella di bufala. Buffalo milk is much richer than cow's milk, so mozzarella and Indian milk dishes are very different when the traditional buffalo milk is replaced with cow's milk. Buffalo milk is much richer than cow's milk, so mozzarella and Indian milk dishes are very different when the traditional buffalo milk is replaced with cow's milk.

The Yak The third important dairy bovine is the yak, The third important dairy bovine is the yak, Bos grunniens. Bos grunniens. This long-haired, bushy-tailed cousin of the common cow is beautifully adapted to the thin, cold, dry air and spa.r.s.e vegetation of the Tibetan plateau and mountains of central Asia. It was domesticated around the same time as lowland cattle. Yak milk is substantially richer in fat and protein than cow milk. Tibetans in particular make elaborate use of yak b.u.t.ter and various fermented products. This long-haired, bushy-tailed cousin of the common cow is beautifully adapted to the thin, cold, dry air and spa.r.s.e vegetation of the Tibetan plateau and mountains of central Asia. It was domesticated around the same time as lowland cattle. Yak milk is substantially richer in fat and protein than cow milk. Tibetans in particular make elaborate use of yak b.u.t.ter and various fermented products.

The Goat The goat and sheep belong to the "ovicaprid" branch of the ruminant family, smaller animals that are especially at home in mountainous country. The goat, The goat and sheep belong to the "ovicaprid" branch of the ruminant family, smaller animals that are especially at home in mountainous country. The goat, Capra hircus, Capra hircus, comes from a denizen of the mountains and semidesert regions of central Asia, and was probably the first animal after the dog to be domesticated, between 8000 and 9000 comes from a denizen of the mountains and semidesert regions of central Asia, and was probably the first animal after the dog to be domesticated, between 8000 and 9000 BCE BCE in present-day Iran and Iraq. It is the hardiest of the Eurasian dairy animals, and will browse just about any sort of vegetation, including woody scrub. Its omnivorous nature, small size, and good yield of distinctively flavored milk - the highest of any dairy animal for its body weight - have made it a versatile milk and meat animal in marginal agricultural areas. in present-day Iran and Iraq. It is the hardiest of the Eurasian dairy animals, and will browse just about any sort of vegetation, including woody scrub. Its omnivorous nature, small size, and good yield of distinctively flavored milk - the highest of any dairy animal for its body weight - have made it a versatile milk and meat animal in marginal agricultural areas.

The Sheep The sheep, The sheep, Ovis aries, Ovis aries, was domesticated in the same region and period as its close cousin the goat, and came to be valued and bred for meat, milk, wool, and fat. Sheep were originally grazers on gra.s.sy foothills and are somewhat more fastidious than goats, but less so than cattle. Sheep's milk is as rich as the buffalo's in fat, and even richer in protein; it has long been valued in the Eastern Mediterranean for making yogurt and feta cheese, and elsewhere in Europe for such cheeses as Roquefort and pecorino. was domesticated in the same region and period as its close cousin the goat, and came to be valued and bred for meat, milk, wool, and fat. Sheep were originally grazers on gra.s.sy foothills and are somewhat more fastidious than goats, but less so than cattle. Sheep's milk is as rich as the buffalo's in fat, and even richer in protein; it has long been valued in the Eastern Mediterranean for making yogurt and feta cheese, and elsewhere in Europe for such cheeses as Roquefort and pecorino.

The Camel The camel family is fairly far removed from both the bovids and ovicaprids, and may have developed the habit of rumination independently during its early evolution in North America. Camels are well adapted to arid climates, and were domesticated around 2500 The camel family is fairly far removed from both the bovids and ovicaprids, and may have developed the habit of rumination independently during its early evolution in North America. Camels are well adapted to arid climates, and were domesticated around 2500 BCE BCE in central Asia, primarily as pack animals. Their milk, which is roughly comparable to cow's milk, is collected in many countries, and in northeast Africa is a staple food. in central Asia, primarily as pack animals. Their milk, which is roughly comparable to cow's milk, is collected in many countries, and in northeast Africa is a staple food.

The Origins of Dairying When and why did humans extend our biological heritage as milk drinkers to the cultural practice of drinking the milk of other other animals? Archaeological evidence suggests that sheep and goats were domesticated in the gra.s.slands and open forest of present-day Iran and Iraq between 8000 and 9000 animals? Archaeological evidence suggests that sheep and goats were domesticated in the gra.s.slands and open forest of present-day Iran and Iraq between 8000 and 9000 BCE BCE, a thousand years before the far larger, fiercer cattle. At first these animals would have been kept for meat and skins, but the discovery of milking was a significant advance. Dairy animals could produce the nutritional equivalent of a slaughtered meat animal or more each year for several years, and in manageable daily increments. Dairying is the most efficient means of obtaining nourishment from uncultivated land, and may have been especially important as farming communities spread outward from Southwest Asia.

Small ruminants and then cattle were almost surely first milked into containers fashioned from skins or animal stomachs. The earliest hard evidence of dairying to date consists of clay sieves, which have been found in the settlements of the earliest northern European farmers, from around 5000 BCE BCE. Rock drawings of milking scenes were made a thousand years later in the Sahara, and what appear to be the remains of cheese have been found in Egyptian tombs of 2300 BCE BCE.

Diverse Traditions Early shepherds would have discovered the major transformations of milk in their first containers. When milk is left to stand, fat-enriched cream naturally forms at the top, and if agitated, the cream becomes b.u.t.ter. The remaining milk naturally turns acid and curdles into thick yogurt, which draining separates into solid curd and liquid whey. Salting the fresh curd produces a simple, long-keeping cheese. As dairyers became more adept and harvested greater quant.i.ties of milk, they found new ways to concentrate and preserve its nourishment, and developed distinctive dairy products in the different climatic regions of the Old World.

In arid southwest Asia, goat and sheep milk was lightly fermented into yogurt that could be kept for several days, sun-dried, or kept under oil; or curdled into cheese that could be eaten fresh or preserved by drying or brining. Lacking the settled life that makes it possible to brew beer from grain or wine from grapes, the nomadic Tartars even fermented mare's milk into lightly alcoholic koumiss, koumiss, which Marco Polo described as having "the qualities and flavor of white wine." In the high country of Mongolia and Tibet, cow, camel, and yak milk was churned to b.u.t.ter for use as a high-energy staple food. which Marco Polo described as having "the qualities and flavor of white wine." In the high country of Mongolia and Tibet, cow, camel, and yak milk was churned to b.u.t.ter for use as a high-energy staple food.

In semitropical India, most zebu and buffalo milk was allowed to sour overnight into a yogurt, then churned to yield b.u.t.termilk and b.u.t.ter, which when clarified into ghee ghee (p. 37) would keep for months. Some milk was repeatedly boiled to keep it sweet, and then preserved not with salt, but by the combination of sugar and long, dehydrating cooking (see box, p. 26). (p. 37) would keep for months. Some milk was repeatedly boiled to keep it sweet, and then preserved not with salt, but by the combination of sugar and long, dehydrating cooking (see box, p. 26).

The Mediterranean world of Greece and Rome used economical olive oil rather than b.u.t.ter, but esteemed cheese. The Roman Pliny praised cheeses from distant provinces that are now parts of France and Switzerland. And indeed cheese making reached its zenith in continental and northern Europe, thanks to abundant pastureland ideal for cattle, and a temperate climate that allowed long, gradual fermentations.

The one major region of the Old World not to embrace dairying was China, perhaps because Chinese agriculture began where the natural vegetation runs to often toxic relatives of wormwood and epazote rather than ruminant-friendly gra.s.ses. Even so, frequent contact with central Asian nomads introduced a variety of dairy products to China, whose elite long enjoyed yogurt, koumiss, b.u.t.ter, acid-set curds, and, around 1300 and thanks to the Mongols, even milk in their tea!

Dairying was unknown in the New World. On his second voyage in 1493, Columbus brought sheep, goats, and the first of the Spanish longhorn cattle that would proliferate in Mexico and Texas.

Milk in Europe and America: From Farmhouse to Factory Preindustrial Europe In Europe, dairying took hold on land that supported abundant pasturage but was less suited to the cultivation of wheat and other grains: wet Dutch lowlands, the heavy soils of western France and its high, rocky central ma.s.sif, the cool, moist British Isles and Scandinavia, alpine valleys in Switzerland and Austria. With time, livestock were selected for the climate and needs of different regions, and diversified into hundreds of distinctive local breeds (the rugged Brown Swiss cow for cheesemaking in the mountains, the diminutive Jersey and Guernsey for making b.u.t.ter in the Channel Islands). Summer milk was preserved in equally distinctive local cheeses. By medieval times, fame had come to French Roquefort and Brie, Swiss Appenzeller, and Italian Parmesan. In the Renaissance, the Low Countries were renowned for their b.u.t.ter and exported their productive Friesian cattle throughout Europe. In Europe, dairying took hold on land that supported abundant pasturage but was less suited to the cultivation of wheat and other grains: wet Dutch lowlands, the heavy soils of western France and its high, rocky central ma.s.sif, the cool, moist British Isles and Scandinavia, alpine valleys in Switzerland and Austria. With time, livestock were selected for the climate and needs of different regions, and diversified into hundreds of distinctive local breeds (the rugged Brown Swiss cow for cheesemaking in the mountains, the diminutive Jersey and Guernsey for making b.u.t.ter in the Channel Islands). Summer milk was preserved in equally distinctive local cheeses. By medieval times, fame had come to French Roquefort and Brie, Swiss Appenzeller, and Italian Parmesan. In the Renaissance, the Low Countries were renowned for their b.u.t.ter and exported their productive Friesian cattle throughout Europe.

Until industrial times, dairying was done on the farm, and in many countries mainly by women, who milked the animals in early morning and after noon and then worked for hours to churn b.u.t.ter or make cheese. Country people could enjoy good fresh milk, but in the cities, with confined cattle fed inadequately on spent brewers' grain, most people saw only watered-down, adulterated, contaminated milk hauled in open containers through the streets. Tainted milk was a major cause of child mortality in early Victorian times.

Industrial and Scientific Innovations Beginning around 1830, industrialization transformed European and American dairying. The railroads made it possible to get fresh country milk to the cities, where rising urban populations and incomes fueled demand, and new laws regulated milk quality. Steam-powered farm machinery meant that cattle could be bred and raised for milk production alone, not for a compromise between milk and hauling, so milk production boomed, and more than ever was drunk fresh. With the invention of machines for milking, cream separation, and churning, dairying gradually moved out the hands of milkmaids and off the farms, which increasingly supplied milk to factories for ma.s.s production of cream, b.u.t.ter, and cheese. Beginning around 1830, industrialization transformed European and American dairying. The railroads made it possible to get fresh country milk to the cities, where rising urban populations and incomes fueled demand, and new laws regulated milk quality. Steam-powered farm machinery meant that cattle could be bred and raised for milk production alone, not for a compromise between milk and hauling, so milk production boomed, and more than ever was drunk fresh. With the invention of machines for milking, cream separation, and churning, dairying gradually moved out the hands of milkmaids and off the farms, which increasingly supplied milk to factories for ma.s.s production of cream, b.u.t.ter, and cheese.

From the end of the 19th century, chemical and biological innovations have helped make dairy products at once more hygienic, more predictable, and more uniform. The great French chemist Louis Pasteur inspired two fundamental changes in dairy practice: pasteurization, pasteurization, the pathogen-killing heat treatment that bears his name; and the use of standard, purified microbial cultures to make cheeses and other fermented foods. Most traditional cattle breeds have been abandoned in favor of high-yielding black-and-white Friesian (Holstein) cows, which now account for 90% of all American dairy cattle and 85% of British. The cows are farmed in ever larger herds and fed an optimized diet that seldom includes fresh pasturage, so most modern milk lacks the color, flavor, and seasonal variation of preindustrial milk. the pathogen-killing heat treatment that bears his name; and the use of standard, purified microbial cultures to make cheeses and other fermented foods. Most traditional cattle breeds have been abandoned in favor of high-yielding black-and-white Friesian (Holstein) cows, which now account for 90% of all American dairy cattle and 85% of British. The cows are farmed in ever larger herds and fed an optimized diet that seldom includes fresh pasturage, so most modern milk lacks the color, flavor, and seasonal variation of preindustrial milk.

Dairy Products Today Today dairying is split into several big businesses with nothing of the dairymaid left about them. b.u.t.ter and cheese, once prized, delicate concentrates of milk's goodness, have become inexpensive, ma.s.s-produced, uninspiring commodities piling up in government warehouses. Manufacturers now remove much of what makes milk, cheese, ice cream, and b.u.t.ter distinctive and pleasurable: they remove milk fat, which suddenly became undesirable when medical scientists found that saturated milk fat tends to raise blood cholesterol levels and can contribute to heart disease. Happily the last few years have brought a correction in the view of saturated fat, a reaction to the juggernaut of ma.s.s production, and a resurgent interest in full-flavored dairy products crafted on a small scale from traditional breeds that graze seasonally on green pastures. Today dairying is split into several big businesses with nothing of the dairymaid left about them. b.u.t.ter and cheese, once prized, delicate concentrates of milk's goodness, have become inexpensive, ma.s.s-produced, uninspiring commodities piling up in government warehouses. Manufacturers now remove much of what makes milk, cheese, ice cream, and b.u.t.ter distinctive and pleasurable: they remove milk fat, which suddenly became undesirable when medical scientists found that saturated milk fat tends to raise blood cholesterol levels and can contribute to heart disease. Happily the last few years have brought a correction in the view of saturated fat, a reaction to the juggernaut of ma.s.s production, and a resurgent interest in full-flavored dairy products crafted on a small scale from traditional breeds that graze seasonally on green pastures.

Milk and Health Milk has long been synonymous with wholesome, fundamental nutrition, and for good reason: unlike most of our foods, it is actually designed to be a food. As the sole sustaining food of the calf at the beginning of its life, it's a rich source of many essential body-building nutrients, particularly protein, sugars and fat, vitamin A, the B vitamins, and calcium.

Food Words: Milk Milk and and Dairy DairyIn their roots, both milk milk and and dairy dairy recall the physical effort it once took to obtain milk and transform it by hand. recall the physical effort it once took to obtain milk and transform it by hand. Milk Milk comes from an Indo-European root that meant both "milk" and "to rub off," the connection perhaps being the stroking necessary to squeeze milk from the teat. In medieval times, comes from an Indo-European root that meant both "milk" and "to rub off," the connection perhaps being the stroking necessary to squeeze milk from the teat. In medieval times, dairy dairy was originally was originally dey-ery, dey-ery, meaning the room in which the meaning the room in which the dey, dey, or woman servant, made milk into b.u.t.ter and cheese. or woman servant, made milk into b.u.t.ter and cheese. Dey Dey in turn came from a root meaning "to knead bread" ( in turn came from a root meaning "to knead bread" (lady shares this root) - perhaps a reflection not only of the servant's several duties, but also of the kneading required to squeeze b.u.t.termilk out of b.u.t.ter (p. 34) and sometimes the whey out of cheese. shares this root) - perhaps a reflection not only of the servant's several duties, but also of the kneading required to squeeze b.u.t.termilk out of b.u.t.ter (p. 34) and sometimes the whey out of cheese.

Over the last few decades, however, the idealized portrait of milk has become more shaded. We've learned that the balance of nutrients in cow's milk doesn't meet the needs of human infants, that most adult humans on the planet can't digest the milk sugar called lactose, that the best route to calcium balance may not be ma.s.sive milk intake. These complications help remind us that milk was designed to be a food for the young and rapidly growing calf, not for the young or mature human.

Milk Nutrients Nearly all milks contain the same battery of nutrients, the relative proportions of which vary greatly from species to species. Generally, animals that grow rapidly are fed with milk high in protein and minerals. A calf doubles its weight at birth in 50 days, a human infant in 100; sure enough, cow's milk contains more than double the protein and minerals of mother's milk. Of the major nutrients, ruminant milk is seriously lacking only in iron and in vitamin C. Thanks to the rumen microbes, which convert the unsaturated fatty acids of gra.s.s and grain into saturated fatty acids, the milk fat of ruminant animals is the most highly saturated of our common foods. Only coconut oil beats it. Saturated fat does raise blood cholesterol levels, and high blood cholesterol is a.s.sociated with an increased risk of heart disease; but the other foods in a balanced diet can compensate for this disadvantage (p. 253).

The box below shows the nutrient contents of both familiar and unfamiliar milks. These figures are only a rough guide, as the breakdown by breed indicates; there's also much variation from animal to animal, and in a given animal's milk as its lactation period progresses.

The Compositions of Various MilksThe figures in the following table are the percent of the milk's weight accounted for by its major components.

Milk Fat Fat Protein Protein Lactose Lactose

Human 4.0 4.0.

1.1 1.1.

6.8 6.8.

Cow 3.7 3.7.

3.4 3.4.

4.8 4.8.

Holstein/Friesian 3.6 3.6.

3.4 3.4.

4.9 4.9.

Brown Swiss 4.0 4.0.

3.6 3.6.